International Journal of Pharmaceutics 453 (2013) 433–440 Contents lists available at SciVerse ScienceDirect International Journal of Pharmaceutics j o ur nal ho me page: www.elsevier.com/locate/ijpharm In vitro study of the cytotoxicity and antiproliferative effects of surfactants produced by Sphingobacterium detergens César Burgos-Díaz a,b , Raquel Martín-Venegas c , Verónica Martínez c , Carolina Emilia Storniolo c , José Antonio Teruel d , Francisco José Aranda d , Antonio Ortiz d , Ángeles Manresa a , Ruth Ferrer c , Ana M. Marqués a,∗ a Laboratori de Microbiologia, Facultat de Farmàcia, Universitat de Barcelona. Av. Joan XIII s/n, 08028 Barcelona, Spain b Agriaquaculture Nutritional Genomic Center, CGNA, Technology and Processes Unit, Francisco Salazar 01145, UFRO, Temuco, Chile c Department de Fisiologia, Facultat de Farmàcia, Universitat de Barcelona. Av. Joan XIII s/n, 08028 Barcelona, Spain d Departamento de Bioquímica y Biología Molecular-A, Facultad de Veterinaria, Universidad de Murcia, 301000 Murcia, Spain a r t i c l e i n f o Article history: Received 5 April 2013 Received in revised form 10 June 2013 Accepted 12 June 2013 Available online 24 June 2013 Keywords: Biosurfactants Haemolysis Apoptosis Caco-2 cells 3T3 fibroblasts HaCaT keratinocytes a b s t r a c t The application of biosurfactants in the biomedical field is growing due to their antimicrobial activity, low cytotoxicity and ability to induce apoptosis in cancer cells. In the light of this therapeutic potential, as well as possible applications in cosmetics or as drug vehicles in pharmaceutical products, a new biosurfactant produced by Sphingobacterium detergens was investigated for its haemolytic activity and cytotoxic and antiproliferative effects in different cell lines. Fraction A showed 100% haemolysis in rabbit erythrocytes, but in Fraction B the rate was only 83%. When comparing cytotoxicity values (IC 50 ) of the two fractions in model fibroblast and keratinocyte cell cultures, Fraction B was less cytotoxic, showing lower values than the reference compound SDS, indicating low skin irritability. Finally, in non-differentiated intestinal Caco- 2 cultures, Fractions A and B reduced cell proliferation and induced apoptosis by 44% and 75%, respectively. According to these results, biosurfactants produced by S. detergens have potential application in cosmetic and pharmaceutical formulations. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Chemically synthesized surfactants are amphiphilic compounds capable of reducing surface and interfacial tension and increas- ing the solubility and bioavailability of hydrophobic or insoluble organic compounds (Singh et al., 2007). The large surface-to- volume ratio of bacteria favors the production of biosurfactants (BS) with a diverse chemical nature, including glycolipids, lipopeptides, phospholipids, fatty acids, neutral lipids and polymeric or particu- late compounds (Kopade et al., 2012). BS have important potential biotechnological applications in industry and medicine, constitut- ing a possible attractive alternative to their synthetic chemical counterparts due to their biodegradability and lower toxicity (Singh et al., 2007). Intense research activity is currently being directed toward the identification of new BS and the characterization of their chemical and biological properties. Compared with synthetic alternatives, BS are generally more selective, effective and stable, presenting a number of promising technical applications (Aranda et al., 2005). Biological and environmental compatibility also favor the use of BS ∗ Corresponding author. Tel.: +34 934024496; fax: +34 934024498. E-mail address: ammarques@ub.edu (A.M. Marqués). (Sánchez et al., 2010; Zaragoza et al., 2009). Although their high production costs are a limiting factor in large-volume applications, the relatively low effective concentration of BS in biological sys- tems could facilitate their usage in high added value products. BS application in products for human consumption, for instance, in cosmetics and especially pharmaceuticals, requires an accu- rate characterization of possible toxic side effects (Sánchez et al., 2010). Thus, since surfactants are one of the most versatile and frequently applied excipients, it is necessary to study their poten- tial to cause dermal and ocular irritation to guarantee that they do not provoke unacceptable or irreversible damage to the skin or eye at the concentrations employed in formulations (Benavides et al., 2004b). Additionally, there is a growing interest in the study of the physicochemical and biological properties of new BS because of their potential pharmaceutical applications as active principles (Sánchez et al., 2010; Banat et al., 2000; Desai and Banat, 1997). Biological activities displayed by BS include antimicrobial, antivi- ral, antitumoral, and immunomodulation (Benavides et al., 2004a; Singh et al., 2007; Sánchez et al., 2010). A comprehensive knowl- edge of the biological function of BS in mammalian cells is crucial for the effective design and development of appropriate material as powerful tools for medical devices, tissue engineering, and drug delivery systems (Kusumoto and Ishikawa, 2010). 0378-5173/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.ijpharm.2013.06.029